#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ #include<iostream> // cin\cout\endl using namespace std; int main(){ int n; cin>>n; switch(n){ case 1: case 3: case 5: case 7: case 8: case 10: case 12:cout<<31<<endl;break; case 2:cout<<29<<endl;break; case 4: case 6: case 9: case 11:cout<<30<<endl;break; default: cout<<"lnvalid."<<endl;break; } return 0; }